Grinding mill



Nov. 9 1926.

E. BURY GRINDING MILL Filed May 8, 1925 2 Sheets-Sheet 1 ATTORNEYS.

Patented Nov. 9, i926.

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air era-e GnrN'iJING MILL.

Application filed May 8, i925. Serial No. zarss.

This invention, stated in its broadest more especial relation to coffee grinding mills. More specifically stated, the invention relates to coffee grinding mills which are provided upper and lower milling cutters of the rotatable type and grinding shoes complementalto each cutter. Prac- 'ticeciictates that in this particulartype of W grinding mill the upper 'milling cutteris capable of grinding a fixed quantity of material at all times whereas the lower milling cutter will only properly function in accordance with the degree of finenessto which the material is to be finally ground or cut. Stated in other words, the upper milling cutter is for the purpose of a- "preliminary breaking, crushing or cutting of material and the lower milling cutter is for the purpose of completing the grinding operation. Practice dictates that in the normal operation of a mill of the character under consideration there results between the upper and lower cutters an accumulation or backing-up 'of material being ground with the result that the upper milling cutter during rotation will turn the accumulated materialand tend to draw it up around the curve and regrind it, thus destroying theappearance of the product. Further, additional power is required to operate the mill because of the double grinding resulting. Further, if the mill becomes too fully charged, jamming of the parts results which has a tendency to throw the operating bolt from the pulley and also to stall the operating motor.

The leading object of the present invention is to overcome these above described disadvantageous features and provide a grinding mill in which regrinding of the material is eliminated; belt throwing and motor stalling eliminated; conservation of motor power maintained: aunuch'clea'ner and more uniform degree of grinding efjfected; and general efficiency and satisfactory operation maintained. I

A 'f'urtherfobject of the present invention to provide an arrangement, 'e'o nbination and ceirnectiener partsror at' ningthe resultsf'sou'ghtby tlie'le'ading object. v

Other and further objects not at this Y nrorespeeifi'cali arterreferre peineea an "ear he hereinfemale;

Theinvention consists of the novel construction hereinafter described and finally claimed.

The nature, characteristic features and scope of the invention will be more fully understood from the following description taken in connection with the accompanying drawings forming part hereof, and in which Fig. 1, is a view in vertical section ofia grinding mill embodying the features of the present invention.

Fig. 2, is a view in vertical section taken upon the line 22 of Fig.1.

Fig. 3, is a view in perspective of the combined gate and closure plate shown in the foregoing figures.

Fig. 4, is a fragmentary view in vertical section illustrating grinding mill equipped with the modified form ofcombined gate and closure plate.

' Fig. 5, is a similar view of a further modified form.

Fig. 6, is a similar view of a still further modified form.

For the purpose of illustratingmy invention I have shown in the accompanying drawings several forms thereof which are at present preferred by me, since the same have been found in practice to give satisfactory and reliable results,'although it to be understood that the various instrumentalities of which my invention consists canbe variously arranged and organized and that my lnvention is not limited to the precise arrangement and organization of the instrumentalities as herein shownand described.

Referring to the drawings in detail the reference numeral '1 designates a, housing provided at its top with a feed hopper 2. Rotatably mounted within housing l upo'n a horizontal shaft 3 is a milling cutter 4: which cutter is arranged immediately below hopper 2. The grinding cutteris of any well known and conventional form. The reference numeral v 5 designates a grinding shoewhich ispivotally' -mounted. as at 56, and is provided witha'iiose'l at its npperend,

"thj 'saii d "grinding is'ho'e being adjustable toward" or awayfroi'n theniilling "cutteres i f'wll understoodfin' tlie art. Mounted in ing shoe 1O pivoted as at 11 is also provided for co-operation with milling cutter 9 and is also capable of adjustment toward or away from the cutter 9 as is well understood in the art. With especial reference now to Figs. 1 to 3 inclusive, the reference numeral 12 designates a gate and the reference numeral 13 a closure plate. The gate and plate, as clearly shown in Fig. 3, comprise a unitary structure and are arranged to function in synchronism. The gate 12 at each end is provided with an arm 14: which terminates in a bearing 15, said bearings 15 being penetrated by shaft 3 so that the gate 12 normally maintains a vertical position as shown in Fig. 1, and its lower edge is slightly spaced from the periphery of the milling cutter 9. Pivoted as at 16 to the housing 1 is the closure plate 13 which is normally at an inclination above the milling cutter 4. Thus, while the gate 12 is vertically disposed the plate 13 is in a plane substantially at right angles to the vertical plane of gate 12. Connecting each side of the gate 12 with the closure plate 13 are a pair of curved arms 17 and links 18 which links have pivotal connection with an arm and with one side of plate 13. Thus, movement of the gate 12 to the right in Fig. 1 will cause the closure plate 13 to move upwardly in abutting relation with the nose 7 of the grinding shoe 5. In order to provide a snug fit the inner side walls of housing 1 are cut away as at 19 so that the ends of the gate 12 may work in said cut-away portions 19.

' In operation the material to be ground passes from hopper 2 to the upper milling cutter at at which place the material is crushed, ground, or cut to what may be said to be a preliminary condition. As the material falls to the lower or main milling cutter 9 there is a tendency for the material to accumulate upon the cutter 9. Persistent accumulation of the material exerts pressure against the gate 12 causing it to swing to the right in Fig. 1, whereupon the free end of the closure plate is caused to abut against nose 7 of grinding shoe 5 to prevent further feeding of material from hopper 2 for the time being. As the lower cutter 9 clears itself of backed-up material the gate 12 moves toward the left in Fig. 1 thus withdrawing closure platev 13 from nose 7 to permit further feed from hopper 2. Thus, the

lower milling cutter is never charged with,

more material than can be conveniently carried 01f. A constant vibratory movement is maintained by the combined gate 12 and plate 13 so that these parts in operation of the mill are in constant motion so that just the proper amount of material is caused to pass to the milling cutters. Thus the two milling cutters work in perfect unison and t e d a w fiieiea wres r d ,top of the closure plate by links mill. If desired a rotatable brush 20 may be provided for cleaning the surface of the lower milling cutter 9. This brush 20 is pivotally suspended as at 21 and is preferably provided with a spring pressed device 22 for maintaining the brush in contact with the surface of the milling cutter.

Referring now to Fig. 4, the construction of housing and cutters are the same as those previously described. However, the combined gate and closure plate are slightly modified in thatthe gate 23 is pivotally supported at 24: within the housing 1 instead of being suspended from shaft 3. The closure plate is connected with respect to gate 23 by means of curved arms 25 pivoted at 26 to the closure plate and pivoted as at 27 to the gate 23. The gate and closure plate function in exactly the same manner as in the operation first described.

Referring to Fig. 5, the gate 28 instead of being aligned with shafts 3 and 8 is arranged in a plane to one side of said shafts and is provided with arms 29 for supporting said gate upon shaft The arms 29 in turn are provided with curved arms 30 which arms are connected to the closure plate by links 31 having pivotal connection between said closure plate and said arms. As thus arranged, while the general operation is the same it may be stated that the arrangement of gate provides for a more sensitive functioning since similar quantities of accumulated material being ground will cause the gate to operate.

In Fig. (5, the gate 32 is supported from shaft 3 as before described but the curved arms 33 are extended upwardly and above the closure plate and are connected to the 33 each link having pivotal relation with a curved arm 33 and with the closure plate. In each of the modified forms just described the side walls of the housing 1 are cut away as at 19 previously described to accommodate the ends of the gates.

A. grinding mill of the character just de scribed not only overcomes the various disadvantageous features enumerated in the beginning of the present specification but provides an efficient, economical and satisfactorily operating grinding mill to prevent the annoyance of jamming, belt throwing, motor stalling, and regrinding and mashing by the upper milling cutter, requires less power to operate, provides a much cleaner and more uniform finished product, eliminates regrinding and provides means which may be properly adjusted for predetermined grade of ground material.

Having thus described'my invention, what I claim as new and desire to secure by Letters Patent, is:

1.;Afidevice of the character stated comprising in combination a feed-hopper, an

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upper, revoluble milling cutter including its complemental grinding shoe, a lower revoluble milling cutter including its complemental grinding shoe, and means including a pivotal upwardly movable closuue plate operative to prevent feeding of material from said hopper to said upper cutter at pie-determined intervals.

2. A device of the character stated, comprising in combination a feed hopper, an upper, revoluble milling cutter including its complemental grinding shoe, a lower revoluble milling cutter including its complemental grinding shoe, and means including a laterally swinging gate and an upwardly .novable closure plate connected with said gate operative. to prevent feeding of material 'from said hopper to said upper cutter at pre-determined intervals.

3. A device of the character stated, comprising in combination a feed hopper, an upper, revoluble milling cutter including its complemental grinding shoe, a lower revolu ble milling cutter including its complemental grinding shoe, and means including a swinging gate and a closure plate connect-ed by means of a curved arm and a link operative to prevent feeding of material from said hopper to said upper cutter at pre-determined intervals.

l. A device of the character stated, comprising in combination a feed hopper, an upper, revoluble. milling cutter including its complemental grinding shoe, a lower revoluble milling cutter including its complemental grinding shoe, a swinging gate arranged above the lower cutter, a closure plate piv otally supported above the upper cutter and means connecting said gate and plate to ensure unison of movement.

5. A device of the character stated comprising in combination, a housing, a feed hopper, an upper revoluble milling cutter within said housing below said hopper, a

' grinding shoe pivoted opposite said upper cutter, a closure plate pivoted within said housing and adapted to have its lower end abut against the upper end of said shoe, a lower revoluble milling cutter including its complemental milling cutter arranged below the upper cutter, a swinging gate arranged above the lower cutter and means connecting said gate and plate.

6. A device of the character stated comprising in combination, a housing the side walls of which are recessed, a feed hopper,

an upper, revoluble milling cutter within said housing below said hopper, a grinding shoe pivoted opposite said upper cutter, a closure plate pivoted within said housing and adapted to have its lower end abut against the upper end of said shoe, a lower revoluble milling cutter including its complemental milling cutter arranged below the upper cutter, a swinging gate arranged above the lower cutter the ends of said gate being guided in the recessed portions of the housing side walls, and means connecting said gate and plate.

7. A device of the character stated comprising in combination, a housing, a feed hopper, an upper, revoluble milling cutter within said housingbelow said hopper, a grinding shoe pivoted opposite said upper cutter, a closure plate pivoted within said housing and adapted to have its lower end abut against the. upper end of said shoe, a lower revoluble milling cutter arranged below the upper cutter, a swinging gate arranged above the lower cutter, and means including a curved arm connecting said gate and plate.

8. As a new article of manufacture a combined gate and closure plate comprising a substantially vertical gate the opposite ends of which are provided with arms for swinging suspension, a closure plate arranged for pivotal suspension in a plane substantially at right angles to said gate and means connecting each end of said gate with said plate.

9. As a new article of manufacture combined gate and closure plate comprising a substantially vertical gate the opposite ends of which are provided with arms for swinging suspension, a closure plate arranged for pivotal suspension in a plane substantially at right angles to said gate and means in cluding a curved arm connecting each end of said gate with said plate.

10. As a new article of manufacture a combined gate and closure plate comprising a substantially vertical gate the opposite ends of which are provided with arms for swinging suspension, a closure plate arranged for pivotal suspension in a plane substantially at right angles to said gate, means including a curved arm connecting each end of said gate with said plate, and means for pivotally connecting said arms with respect to said gate and plate.

EDMUND BURY.

Nil 

